Microtome anti-roll device



Dec. 27, 1966 J M CORMICK ETAL. 3293,9@6

MICROTOME ANTI-ROLL DEVICE Filed Sept. 29, 1964 5.7 Jam, W @5 UnitedStates Patent 3,293,966 MICRUTOME ANTI-ROLL DEVICE James ll McCormick,La Grange, and Leighton C.

Johnson, Westmont, llllL, assignors to Miles Laboratories, Inc.,Elkhart, End, a corporation of indiana Fiied Sept. 29, 1964, Ser. No.399,982 7 Claims. (Oi. 83109) The present invention relates to thepreparation of specimen for microscopic examination. Mere particularly,it relates to an improved method and apparatus for removing a very thinsection from a specimen.

In the microscopic examination of certain specimen such as, for example,specimen of animal tissue or the like, it is customary to remove fromthe specimen a number of thin slices or sections which are then placedon a transparent slide for viewing in a microscope. Frequently, thesection is only a few microns in thickness; hence, it lacks structuralstrength and, as a result, has a tendency to curl or roll into acylinder as it is being formed, thus rendering it unsuitable formounting on a slide. A curled or rolled section can occasionally bestraightened and used, but more often it breaks when an attempt is madeto straighten it due to its extreme thinness.

In many cases, a section curls because the specimen has been improperlyprepared or because the microtome has been improperly adjusted. Both ofthese factors are critical. To slice a section and avoid curling, atechnician usually must have considerable experience. Without suchexperience, a technician generally must employ a time consuming trialand error procedure. Oftentimes, as during a surgical operation, time isof a premium and cannot be spared.

In many instances, one solution to the problem of curling has been touse a soft sable brush to stroke the section and keep it flat as it isformed. This technique requires a very delicate touch and is consideredunsatis factory as a general practice because of its tendency to damagethe section, and because of the difiiculty in operating the microtomeand manipulating the brush at the same time. Therefore, improvements inthis technique are desirable.

The principal object of the present invention is to provide an improvedmethod of removing a thin section from a specimen. Another object it toprovide a device capable of preventing a curling of a section as it isremoved from the specimen. These and other objects of the invention aremore particularly set forth in the following detailed description and inthe accompanying drawings wherein:

FIGURE 1 is a perspective view of a microtome and device showing variousof the features of the invention;

FIGURE 2 is a fragmentary sectional view of the microtome as viewed inthe direction of the arrows 22 of FIGURE 1;

FIGURE 3 is an enlarged perspective view of a por tion of the deviceshown in FIGURE 1; and

FIGURE 4 is a diagrammatic view generally similar to that of FIGURE 2but showing the microtome of FIGURE 1 as a section is being sliced froma specimen.

In general, the present invention is directed to that step in thepreparation of a specimen for microscopic examination in which a thinsection is sliced from the specimen. In accordance with the invention,the section is prevented from curling by the constant a plication ofmechanical pressure to that portion of the specimen first to be removedfrom the specimen in the form of a section. In the illustratedembodiment, this mechanical pressure is provided by means of a device 11mounted on a microtome 13 by means of which the sectioning isaccomplished.

Patented Dec. 27, 1966 Referring now to the drawings, the microtome 13may be of various constructions but, in the illustrated embodiment,comprises a base 15 and a specimen carrier 17 mounted on the base forvertical reciprocal movement as imparted by a manually operated drivemechanism (not shown). The specimen carrier 17 comprises a chuck l9 anda specimen support 21, the chuck 19 being in the form of a blockcentrally recessed to provide an opening within which the specimensupport may be placed. The specimen support 21 may take the form of aflange metal plate, as in the illustrated embodiment, but might also bein the form of a paraflin block within which the specimen is embedded.In either event, the support 21 is held in place within the opening ofthe chuck 19 by a movable jaw 23 suspended adjacent the lower edge ofthe chuck and rendered movable in a vertical direction relative to thechuck by a knob 25.

Slidably mounted on the base 15 is a horizontally disposed plate 27having a pair of depending lugs 29 which support a knife blade 31. Theplate 27 is so connected to the. driving mechanism of the chuck 19 thateach time the chuck is moved through a vertically reciprocating cycle,the plate 27 is moved so as to advance the knife an incremental distancein the direction of a specimen 33 supported by the chuck. Thisincremental degree of advancement is equal to the desired thickness ofthe section 34 and is controlled by an adjusting knob 35 at the side ofthe microtome. Substantial movement of the knife blade relative to thechuck, as foir adjustments and the like, is effected by a feed wheel 3The anti-roll device 11 is preferably mounted on the microtome l3 and,in the illustrated embodiment, is secured to the specimen carrier 17 ofthe microtome. However, the device might also conceivably be supportedon other portions of the microtome as, for example. on the knife 31. Thedevice 11 prevents curling or rolling of the section 34 by engaging thatportion of the specimen which is the first to be removed from thespecimen in the form of a section and urging it into contact with a faceof the knife 31 as the section is cut.

Very generally, the device Ill comprises a U-shaped bail 39 connected bymeans of a hinged supporting structure 41 to the chuck 19 of thespecimen carrier 17 so as to render the device movable with the carrierbut stationary with respect to the specimen itself. In the illustratedembodiment, the bail is positioned so that before the cut is initiated,it will be in engagement with that portion of the face of the specimenimmediately above the lower edge thereof. As the cut is made, theportion engaged by the bail 39 becomes the portion of the section 34,which is then urged by the bail against the face of the knife 31.

More specifically, the hinged supporting structure 41 comprises a hingestrap 43 which is secured, as by machine screws, to the upper surface ofthe chuck 19. The hinge strap 43 carries a pair of upwardly disposedknuckles 45 which pivotally mount a support element 44. A pair of cars48 project upwardly from the opposite ends of the strap and are adaptedto engage the element 44 and permit it to be maintained in a raisedout-of-the-way position for insertion and removal of the specimensupport from the chuck.

The support element 44 is tubular in construction and is generallyU-shaped so as to include a base leg 49, which is rotatably journalledin the knuckles 45, and a pair of outer legs 51. A sleeve 53 is crimpedto the central portion of the base leg 4h and holds the support element44 centered with respect to the hinge strap 43. The legs 51 are bentintermediate their ends so as to form approximately a angle and therebylocate the outer portions of the legs adjacent to the specimen support21. A handle 55 is secured to one of the legs and projects out- J wardlypast the apex or bend thereof to facilitate manipulation of the supportelement.

The bail 39 is in the form of a thin wire bent into a U-shape so as toinclude a central portion or bar 57 which engages the specimen 33 and,later, the section 34, and a pair of generally parallel arms 59 whichare proportioned to telescope within the end portions of the tubularlegs 51 of the support element 44. Preferably, the resiliency of thewire of the bail is such that when the arms 59 are bent slightly out ofparallel, the friction between the arms 59 of the bail and the endportions of the legs 51 of the tubular support element 44 is sufficientto hold the bail in any degree of extension relative to the legs. Thisadjustability of the bail allows it to be maintained at any desiredlevel adjacent the lower portion of the front surface of the specimen33, thus obviating the need for precise positioning of the specimen onthe specimen support 21. This feature is particularly advantageous inthe frozen specimen technique in which a specimen is frozen to thesurface of the support 21, as in the illustrated embodiment.

In the use of the device 11, a specimen support 21 carrying a specimen33 is placed within the chuck 19 of the microtome 13. During suchplacement, the supporting structure 41 and bail 39 are pivoted to araised position and maintained in such position by the cars 48 locatedat opposite sides of the hinge strap 43.

With the specimen support in place, the supporting structure and bailare lowered so as to place the bar 57 of the bail in the vicinity of theouter face of the specimen 33. The bail 39 is then telescopicallyadjusted so as to place the bar in engagement with that portion of thefront face of the specimen which is located just above the lower edge ofthe specimen (see FIGURE 4). Sectioning is now ready to proceed.

As the microtome is operated, the chuck 19 moves downwardly so as toeffect cutting engagement between the specimen and the knife 31, therebyinitiating the cutting of a thin slice or section from the specimen(diagrammatically illustrated in FIGURE 4). During this initial cutting,the section 34 is moved outwardly away from the specimen, but thearrangement of the bail and support 21 provides a gravity bias whichmaintains the bar 57 in contact with the lower edge of the section. Asparticularly shown in FIGURES 2 and 4, the gravity bias includes twocomponents, one of which is directed downwardly on the section beingremoved from the specimen, and the other of which is directed inwardlyon the section toward the specimen. Thus, the weight of the bail bearsdownwardly and inwardly against the front face of the knife blade 31 andprevents initial curling of the section.

As the chuck 19 continues to move downwardly, thereby causing the bladeedge to penetrate further into the specimen, the supporting structure 41and bail 39 pivot slightly upwardly. The continued engagement of the bar57 of the bail with the edge of the section continues to prevent thesection from curling. In addition, surface tension developed between thesection and the face of the knife further reduces the tendency of thesection to curl.

After the blade 31 has passed completely through the specimen 33, thebar 57 of the bail 39 may pass off the face of the lower edge of theknife and thus become disengaged from the section. However, at thispoint the tendency of the section to curl has been essentially overcome,and any tendency which remains is compensated for by surface tension.The bail 39 may then be lifted over the knife blade as the chuck 19 israised and be placed again in contact with the face of the specimen, asbefore, for the cutting of another section.

The device 11 thus prevents curling of the section and is effective evenif other factors which influence the sectioning operation, e.g., thepreparation of the specimen and the adjustment of the microtome, are notideal. The device is uncomplicated and can be utilized by technicians ofmodest experience. It is of simple construction and can be economicallyproduced, yet is durable and not readily subject to breakage ormalfunction.

Various of the features of the invention are set forth in the appendedclaims.

What is claimed is:

1. A microtome comprising a supporting base, a carrier mounted on saidbase adapted to support a specimen, a microtome knife mounted on saidbase adjacent said carrier adapted to slice sections from a given faceof a specimen supported on said carrier incident to a predeterminedengagement between said specimen and knife, means for causing relativemovement between said carrier and said knife so as to effect saidpredetermined engagement, and a device positioned adjacent said carrierfor preventing curling of a section sliced from the specimen, saiddevice including means for mechanically engaging only a single linealong the surface of the section as it is being sliced from thespecimen, said member being pivoted about an axis located on theopposite side of the cutting plane from said section and verticallyabove the upper level of a specimen frozen to said specimen carrier soas to cause said member to bear downwardly and inwardly against thesurface of the section so as to urge the section against the face of theknife blade and thereby prevent the section from curling.

2. A microtome comprising a supporting base, a carrier mounted on saidbase adapted to support a specimen, a microtome knife mounted on saidbase adjacent said carrier adapted to remove sections from a given faceof a specimen supported on said carrier incident to a predeterminedengagement between said specimen and knife, means for causing relativemovement between said carrier and said knife so as to effect saidpredetermined engagement, and a device positioned adjacent said carrierfor preventing curling of a section sliced from the specimen, saiddevice including a member pivotally mounted adjacent said carrier andsaid knife and adapted to pivot between a first out of the way positionpermitting complete access to the carrier to permit the mounting of aspecimen thereon and a second position in contact with that portion ofthe specimen first to be removed from the specimen in the form of asection, said member being adapted to remain in contact with the sectionas the section is being removed from the specimen, said member beingpivoted about an axis located on the opposite side of the cutting planefrom said section and vertically above the upper level of a specimenfrozen to said specimen carrier so as to cause said member to beardownwardly and inwardly against the surface of the section so as to urgethe section against the face of the knife blade and thereby prevent thesection from curling.

3. A microtome comprising a supporting base, a carrier mounted on saidbase adapted to support a specimen, a microtome knife mounted on saidbase adjacent said carrier adapted to remove sections from a given faceof a specimen supported on said carrier incident to a predeterminedengagement between said specimen and knife, means for causing relativemovement between said carrier and said knife so as to effect saidpredetermined engagement along a cutting plane, said knife being mountedwith the face of the blade against which said sliced specimen will bearbeing disposed at an angle from said cutting plane, and a devicepositioned adjacent said carrier for preventing curling of a sectionsliced from the specimen, said device including a member pivotallymounted on said specimen carrier and adapted to assume a position incontact with that portion of the specimen first to be removed from thespecimen in the form of a section, said pivot point being on theopposite side of the cutting plane from the side of the sliced sectionsaid member being adapted to remain in contact with the section as thesection is being removed from the specimen said member being pivoted soas to bear downwardly and inwardly against the section so as to urge thesection against said face of said knife blade and thereby prevent thesection from curling.

4. A microtome comprising a supporting base, a carrier mounted on saidbase adapted to support a specimen, a knife mounted on said baseadjacent said carrier adapted to remove sections from a given face of aspecimen supported on said carrier incident to a predeterminedengagement between said specimen and knife, means for causing relativemovement between said carrier and said knife so as to effect saidpredetermined engagement, and a device positioned adjacent said carrierfor preventing curling of a section sliced from the specimen, saiddevice including a bail having a central horizontal bar and a pair offlanking arms, support means telescopically mounting said arms of saidbail, means pivotally mounting said support means on the specimencarrier so that said bar may be moved between a lower position whereinit gravitationally bears against the front surface of the specimen andan upper position spaced away from the specimen, and means forfrictionally retaining said support means in said upper position.

5. A microtome comprising a base, a specimen carrier mounted on saidbase, a specimen support adapted to support a frozen specimen, meansattaching said specimen support to said specimen carrier, at microtomeknife adapated to slice sections from a given face of a specimen frozento said support incident to a predetermined engagement between saidspecimen and knife, means for causing relative movement in a generallyvertical direction between said carrier and said knife so as to effectsaid predetermined engagement, means mounting said microtome knife onsaid base with the cutting edge poining generally upward and with theupper face of the blade disposed at an angle from the cutting planewhich plane is established by the direction of said relative movement,and a device pivotally mounted on said carrier for preventing curling ofa section sliced from the specimen, said device including a memberadapted to contact that portion of the specimen first to be removed fromthe specimen in the form of a section, said member being adapted toremain in contact with the section as the section is being removed fromthe specimen, said member being pivoted so as to bear downwardly andinwardly against the section so as to urge the section against saidupper face of said knife blade and thereby prevent the section fromcurling, said pivot point of the mounting being on the opposite side ofthe cutting plane from said section and at a point vertically above theupper level of a specimen frozen to said specimen support.

6. A microtome comprising a supporting base, a carrier mounted on saidbase adapted to support a specimen, a knife mounted on said baseadjacent said carrier adapted to slice sections from a given face of aspecimen supported on said carrier incident to a predeterminedengagement between said specimen and knife, means for causing relativemovement between said carrier and said knife so as to effect saidpredetermined engagement, and a device positioned adjacent said carrierfor preventing curling of a section sliced from the specimen, saiddevice including a generally horizontally disposed thin bar and an armat one end of said bar, support means telescopically mounting said armto support said bar at different vertical levels, means pivotallymounting said support means on the specimen carrier so that said bar maybe moved between a lower position wherein it gravitationally bearsagainst the front surface of the specimen and an upper position spacedaway from the specimen.

7. A device for use with a microtome and adapted to prevent curling of asection sliced from a specimen by means of the microtome, which devicecomprises a thin bar adapted to be placed to bear only along a line ofcontact with that portion of the specimen which is first to be removedfrom the specimen in the form of a section, and pivot means mountable onthe microtome adapted to pivotally support said bar and maintain it incontact with the above-mentioned portion of the specimen during theformation of the section as the section slides along the face of a knifeblade disposed at an angle to the cutting plane along which the sectionis severed from the speciment, the pivot point being on the oppositeside of the cutting plane from the first-removed portion of thespeciment, said bar thereby being pivotally supported so as to beardownwardly and inwardly against said first-removed portion of thespecimen so as to urge it against the face of said knife blade.

References Cited by the Examiner UNITED STATES PATENTS 8/1953 Roofe etal 83-9155 X 6/1965 McCormick 83-9155

1. A MICROTOME COMPRISING A SUPPORTING BASE, A CARRIER MOUNTED ON SAIDBASE ADAPTED TO SUPPORT A SPECIMEN, A MICROTOME KNIFE MOUNTED ON SAIDBASE ADJACENT SAID CARRIER ADAPTED TO SLICE SECTIONS FROM A GIVEN FACEOF A SPECIMEN SUPPORTED ON SAID CARRIER INCIDENT TO A PREDETERMINEDENGAGEMENT BETWEEN SAID SPECIMEN AND KNIFE, MEANS FOR CAUSING RELATIVEMOVEMENT BETWEEN SAID CARRIER AND SAID KNIFE SO AS TO EFFECT SAIDPREDETERMINED ENGAGEMENT, AND A DEVICE POSITIONED ADJACENT SAID CARRIERFOR PREVENTING CURLING OF A SECTION SLICED FROM THE SPECIMEN, SAIDDEVICE INCLUDING MEANS FOR MECHANICALLY ENGAGING ONLY A SINGLE LINEALONG THE SURFACE OF THE SECTION AS IT IS BEING SLICED FROM THESPECIMEN, SAID MEMBER BEING PIVOTED ABOUT AN AXIS LOCATED ON THEOPPOSITE SIDE OF THE CUTTING PLANE FROM SAID SECTION AND VERTICALLYABOVE THE UPPER LEVEL OF A SPECIMEN FROZEN TO SAID SPECIMEN CARRIER SOAS TO CAUSE SAID MEMBER TO BEAR DOWNWARDLY AND INWARDLY AGAINST THESURFACE OF THE SECTION SO AS TO URGE THE SECTION AGAINST THE FACE OF THEKNIFE BLADE AND THEREBY PREVENT THE SECTION FROM CURLING.